The present invention relates to a hydrostatic mounting of longitudinally displaceably arranged machine parts, in particular a hydrostatic profile rail guide, in which a guide carriage is mounted hydrostatically on a guide rail.
For example, a hydrostatic profile rail guide has become known from WO2004/020852 A1, and in this a guide rail designed with an approximately T-shaped cross-section is surrounded by the guide carriage. The guide carriage has a back and legs located on both sides of the guide rail and adjoining the back in one piece, so that the guide carriage has an approximately U-shaped cross-sectional profile. The free ends of each leg are provided with screw-on flanges which spring toward one another so that the T-shaped guide rail is surrounded.
In this known hydrostatic profile rail guide, pressure pockets for building up a hydrostatic pressure between the guide rail and the guide carriage are provided in a known way on the guide carriage. Hydraulic fluid is pumped into the pressure pockets via an external pump, so that a pressure cushion is built up between the guide carriage and the guide rail. The hydraulic fluid flows out via gaps which are connected hydraulically to the pressure pockets. The gaps are delimited by gap faces which are formed on the guide carriage and on the guide rail.
Furthermore, this known hydrostatic profile rail guide is provided with drainage in order to receive hydraulic fluid which emerges from the gaps. The drainage is connected to a return duct or a reservoir, so that the hydraulic fluid can be supplied to the pump again and pumped anew into the pressure pockets of the hydrostatic profile rail guides.
Furthermore, a seal is provided, which ensures that this known hydrostatic profile rail guide is oil-tight. This seal is arranged effectively between the guide carriage and the guide rail. the seal has side portions and head portions, in each case at least one of the side portions of the seal which extend along the guide rail being arranged between each leg of the guide carriage and of the guide rail. In each case at least one of the head portions of the seal is arranged transversely to the guide rail on the two head sides of the guide carriage. This seal ensures that, even when the pump is switched off and the hydrostatic profile rail guide is at a standstill, no oil escapes in an undesirable way.
The arrangement of the pressure pockets, of the drainage and of the continuous seal requires considerable construction space which, for a given size of a machine part to be supported, is at the expense of the dimensioning of the pressure pockets. In specific applications, a pressure pocket of larger design is desirable, but cannot be implemented technically, because the limited construction space is taken up by the drainage and the seal. This problem applies particularly to hydrostatic profile rail guides which lie in the standard construction space of rolling profile rail guides according to DIN 645-1: there is often the wish to replace rolling profile rail guides by hydrostatic profile rail guides.